Wheel assemblies that utilize wheel appliques to decorate the external or outboard surfaces of plain steel wheels are well known and are far less expensive to produce than decorative wheels that have to be formed and finished.
Wheel appliques can be secured to wheels by various mechanical engaging structures and/or by adhesives. U.S. Pat. No. 5,664,845 to Maloney et al. discloses a vehicle wheel cover retention system in which the annular lip of the wheel cover is configured to spring outwardly into a groove provided in the inner surface of the wheel. U.S. Pat. No. 5,595,423 to Heck et al. discloses a vehicle wheel cover retention system in which the outer end of the wheel cover is deformed to cover the outer peripheral end of the outboard bead seat retaining flange of the wheel. Both U.S. Pat. No. 5,664,845 to Maloney et al. and U.S. Pat. No. 5,595,423 to Heck et al. utilize an adhesive in cooperation with their respective mechanical engaging structures.
Many wheel assemblies include decorative wheel covers that are adhesively attached to underlying wheels. U.S. Pat. No. 3,669,501 to Derleth discloses the use of a foamable adhesive that is used to secure a decorative cover to a wheel. The decorative cover in Derleth is configured to have variations in contour in a direction transverse to the axis of the wheel which exceed the variations in the rim and/or disc contour of the wheel, which variations would be extremely difficult and expensive, if not impossible, to stamp or draw in the disc of the wheel. During assembly, a foamable adhesive is coated on the wheel, and the decorative cover is then quickly clamped to the wheel before the adhesive begins to foam. As the adhesive foams, void spaces between the wheel and cover are filled with the foamable adhesive.
Turbine openings which can be decoratively designed are a necessary element in today's wheel systems in providing proper cooling to brake systems. In addition the aesthetics of endless configurations of turbine openings add individuality and style to a vehicle wheels. The inclusion of turbine openings in wheels and wheel covers creates problems with the use of adhesives. In order to use foamable adhesives, it would be necessary to use some additional structure to seal large openings such as turbine openings to prevent the foamable adhesive from escaping through the openings rather than spread evenly or completely between a wheel and wheel cover.
U.S. Pat. Nos. 5,368,370 and 5,461,779 to Beam disclose an ornamental applique formed on a uniform thickness of stainless steel sheet stock that requires attachment to the wheel by the use of a full surface curable adhesive uniformly deposited between the stainless steel cover and a mechanical locking arrangement. The mechanical locking arrangement consists of an undercut in the rim of the wheel into which the cover nests and a hole in the wheel aligned with a hole in the applique wherein a lug stud is permanently attached to create a mechanical lock that, according to Beam's teachings, compresses the full surface uniform layer of curable adhesive to hold the applique in place until the adhesive cures.
Beam's teachings exemplify an early concern that adhesives used to secure wheel covers onto wheel assemblies had to be applied as continuous coatings between the wheel covers and wheels in order to secure the attachment and prevent moisture and dirt from entering any gaps between the wheel covers and wheels and causing corrosion to develop.
There are some restrictions on the types of adhesives that can be used to secure wheel covers to wheels and considerations on how to apply some adhesives. Suitable adhesives have to withstand the high temperatures generated by tires, wheels and breaking systems. In the case of air-cured and moisture-cured adhesives, it has been discovered that the use of continuous coatings of the adhesives between wheel covers and a wheels adversely effects cure time.
U.S. Pat. No. 5,597,213 to Chase exemplifies the use beads of adhesive that are provide in parallel as separated lines of adhesive rather than a continuous layer to create voids so as to reduce the amount of curing time of the adhesive and thereby reduce manufacturing time and costs. In Chase, air between the lines of adhesives is captured between the overlay and the wheel to assist in curing the adhesive. In the case of adhesives that are moisture-cured, Chase proposes introducing high humidity air into the assembly process and the technique of selective application of the adhesive to establish voids between lines of adhesive that serve to entrap moisture laden air further enhancing cure times and reducing overall costs of the manufacturing process.
U.S. Pat. No. 6,007,158 to Maloney et al. teaches a vehicle cover retention system and method for producing the same. Maloney et al. applies an adhesive in a pattern, which when pressed between the wheel cover and wheel can fill less that the entire gap between the wheel cover and wheel, but nevertheless is effective to prevent water, mud and debris from entering into any voids or gaps between the wheel cover and wheel.
Adhesive patterns exemplified in FIG. 6 of Maloney et al. are designed to establish seals that prevent water, mud and debris from entering any voids, gaps or other spaces between the wheel covers and the wheels. The concern remains that if such water, mud and debris enter any voids, gaps or other spaces between the wheel covers and the wheels, it will eventually cause corrosion to occur between the wheel covers and wheel and result in detachment of the wheel cover or at an unsightly appearance.
The present invention provides a method for adhesively securing decorative wheel covers to wheels which methods involve the use of functional adhesive patterns that are not found in the prior art.